Fourier-transform infrared (FTIR) spectromicroscopy combines the spatial resolution of optical microscopy with the spectral selectivity of vibrational spectroscopy. Synchrotron sources can provide diffraction-limited beams in the infrared, and therefore synchrotron-based FTIR spectromicroscopy is nowadays an indispensable tool for biology and materials science studies where high spatial resolution is required. However, the increasing need for accurate and highly spatially resolved characterization is calling for alternative laboratory-based sources to complement synchrotron radiation. To date, the low brightness of thermal emitters or high temporal coherence and narrow bandwidth or tunability of laser sources have hindered the progress of bench-top FTIR spectromicroscopy. Here, we demonstrate that fiber-based supercontinuum sources in the mid-infrared enable fast spectral mapping of localized material properties with close to diffraction-limited resolution ($3\mathrm{\mu m}\times 3\mathrm{\mu m}$) and pave the way to table-top, on-demand, fast, and highly spatially resolved studies. We illustrate these capabilities by imaging thin sections of human liver samples and compare the results and performance with those obtained using a synchrotron source.

中文翻译：

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基于超连续谱的傅里叶变换红外光谱

傅里叶变换红外（FTIR）光谱显微镜将光学显微镜的空间分辨率与振动光谱的光谱选择性结合在一起。同步辐射源可以在红外光中提供衍射受限的光束，因此，如今，基于同步加速器的FTIR光谱显微镜已成为需要高空间分辨率的生物学和材料科学研究不可缺少的工具。但是，对精确和高度空间分辨的表征的需求不断增长，因此需要替代性的基于实验室的光源来补充同步加速器辐射。迄今为止，热发射器的低亮度或高时间相干性以及激光源的窄带宽或可调谐性已经阻碍了台式FTIR光谱学的发展。这里，$3\mathrm{微米}\times 3\mathrm{微米}$），并为进行桌面式，按需，快速和高度空间解析的研究铺平了道路。我们通过对人体肝脏样本的薄片进行成像来说明这些功能，并将结果和性能与使用同步加速器源获得的结果和性能进行比较。